TR201508479A2 - Noise reducing snorkel tube for recirculation vent hole in air handling system. - Google Patents

Abstract

Vehicle air processing system; blower fan assembly for a vehicle having a return air guide operating between the fan and the fresh air position. The fan is in contact with the fresh air pipe and the recirculation position and the fan is at least partially in contact with the recirculation pipe. The noise reducing end of the recirculation pipe is located under the instrument panel of the vehicle and is oriented substantially perpendicular to a portion of the floor below the instrument panel. Noise from the fan that draws air from the recirculation pipe is directed to the floor below the instrument panel.

Description

DESCRIPTION NOISE REDUCTION SNORKEL TUBE FOR AIR PROCESSING SYSTEM RECIRCULATION VENTILATION HOLE Technical Field to Which the Invention Relates The present invention relates to air processing systems in general and more specifically to a downpipe snorkel pipe for vehicle air processing recirculation functions. State of the Art Related to the Invention (Prior Art) Automobiles generally have air processing systems that deliver various types of cool or cold air to the vehicle passenger compartments. If cooling functions are present, air conditioning is included in the air processing system. Some vehicles may include a recirculation system that draws air from the passenger compartment, which is at least partially cooled by the air conditioning of the vehicle air processing system. The said function may provide additional cooling function for the air delivered to the passenger compartment. DISCUSSION OF THE INVENTION According to one aspect of the present invention, a vehicle air handling system includes a blower fan assembly for a vehicle equipped with a fan and a return air diverter that functions in the fresh air and recirculation positions. In the fresh air position, the fan is in contact with the fresh air duct and in the recirculation position, the fan is in contact with the recirculation duct at least at the top. The recirculation duct is positioned below the vehicle instrument panel to reduce noise and the air conditioning duct is positioned substantially vertically to the floor below the instrument panel. Noise from the fan drawing air through the recirculation duct is directed to the floor below the instrument panel. According to another aspect of the present invention, the vehicle air handling system includes a blower fan assembly disposed in the vehicle instrument panel and having a fan and a recirculation pipe in contact with the fan and a noise attenuated duct located near the lower front corner of the passenger compartment and substantially perpendicular to the floor at the lower front corner. Noise from the fan is directed to the floor at the lower front corner from the noise attenuating duct. According to another aspect of the present invention, the vehicle air handling system includes a blower fan assembly disposed in the vehicle instrument panel and having a fan and a recirculation pipe in contact with the fan and a noise attenuating duct including the longitudinal axis. Noise from the noise attenuating duct is directed to the floor at the longitudinal axis from the noise attenuating duct. The above-mentioned and other features and objects of the present invention will be better understood by those skilled in the art by reviewing the following specification, claims and accompanying drawings. Explanation of the Drawings In the Figures: FIG. 1 is a cross-sectional view of a vehicle in which a recirculation snorkel tube is incorporated in one configuration; FIG. 2 is a top perspective view of a blower fan assembly for a vehicle air handling system in which an alternative configuration of a recirculation snorkel tube is incorporated; FIG. 3 is a first side elevation view of the blower fan assembly of FIG. 2; FIG. 4 is a second half elevation view of the vehicle blower fan assembly of FIG. 2; FIG. 5 is a cross-sectional view of the vehicle blower fan assembly of FIG. 4 taken from line V-V; FIG. 6 is a cross-sectional view of the vehicle blower fan assembly of FIG. 3 taken from line VI-VI; FIG. 7 is an enlarged cross-section of the recirculation snorkel pipe of FIG. 1 taken from area VII; FIG. 8 is a top perspective view of the vehicle blower fan assembly incorporating an alternative configuration of the recirculation snorkel pipe; FIG. 9 is a first side elevation view of the vehicle blower fan assembly of FIG. 7; FIG. 10 is a second side elevation view of the vehicle blower fan assembly of FIG. 7, and FIG. 11 is a cross-sectional view of the vehicle blower fan assembly of FIG. 9, taken at line X-X. Details of the Invention The terms "right," "left," "back," "top," "bottom," "vertical," "horizontal," and derivatives thereof, as used herein for purposes of orientation, relate to the orientations of the invention in FIG. 1. However, within the scope of the present invention, various alternative orientations are possible unless otherwise indicated. It should also be understood that the specific devices and processes illustrated in the accompanying drawings and described in the following description are illustrative embodiments of the inventive concepts defined in the appended claims only. The specific dimensions and other physical properties of the embodiments disclosed herein are not to be taken as a direct reference unless otherwise stated. The reference number 10 generally refers to the blower fan assembly for the air handling system of the vehicle 14, as shown in Figures 1 through 7. The air handling system 12 includes a blower fan assembly for the vehicle 14, and said blower fan assembly includes a fan 16. The return air diverter (18) is positioned in the air treatment system (12) where the fan (16) is in contact with the fresh air pipe (22), in the fresh air position (20), and the fan (16) is in minimal contact with the recirculation snorkel pipe (26), in the recirculation position (24). The noise reducing snorkel pipe (26) is positioned under the instrument panel (30) of the vehicle (14). The noise reducing snorkel pipe (28) is positioned under the instrument panel (30) of the vehicle (14) with a portion of the floor (32) of the vehicle (14) being substantially vertical. The noise passing through the recirculation snorkel tube 26 as a result of the fan 16 drawing air through the recirculation snorkel tube 26 is directed substantially perpendicular to the floor 32 below the instrument panel 30. In this manner, the noise reducing element 28 of the recirculation snorkel tube 26 includes the longitudinal axis 50 and the longitudinal axis 50 of the recirculation snorkel tube 26 is positioned substantially perpendicular to the floor 32 below the instrument panel 30. The recirculation snorkel pipe (26) is arranged to draw air from the lower front area (28) of the passenger compartment (54) of the vehicle (14) in the floor (32) area below the instrument panel (30). The recirculation snorkel pipe (26) is then connected to the upper end (56) of the recirculation snorkel pipe (26) and the air thus drawn can be directed to the blower fan assembly (10). As used herein and as is known by those skilled in the art, the term instrument panel (30) includes the entire front assembly located near the front of the passenger compartment (54) comprising the passenger and driver half doors. The assembly is sometimes referred to as the control panel in common usage. As a result, the area below the instrument panel 30 covers the passenger compartment 54 areas at the feet of the driver and passenger, as well as the areas in between. Again, in accordance with Figures 1 to 7, the blower fan for the air handling system 12 of the vehicle 14 can be positioned behind the instrument panel 30. In this way, the blower fan assembly EKIO and, in particular, the recirculation snorkel pipe 26 can be positioned substantially above the floor of the passenger compartment 54. The location of the blower fan assembly 10, which is separated from the engine compartment 70, substantially limits the amount of air coming from the engine compartment 70 that can be supplied to the air handling system 12 of the vehicle 14. In addition, the blower fan assembly (10) is positioned in such a way that the distance the air must travel to be delivered to the blower fan assembly (10) through the vent holes (72) in the instrument panel (30) and into the passenger compartment (54) is greatly minimized. Depending on the configuration in Figures 1 and 3 to 7, the return air deflector (18) of the air handling system (12) can be positioned in the blower fan assembly (10) for the vehicle (14). In this way, the blower fan assembly (14) is adjusted so that fresh air (78) is drawn into the passenger compartment (54) via the fresh air vehicle (80) in contact with the air conditioner. In various configurations, the return air/preventer (18) functions to recirculate the fresh air between the blower fan assembly (10) and the recirculated air (82) from the passenger compartment (54) via the recirculation snorkel pipe (26) to the passenger compartment (54) via the sufficient quantity of fresh air (78). When the return air diverter (18) is placed in the recirculation position (24), in various configurations the recirculation snorkel position (24) is designed to position the fan (16) in such a way that it contacts both the recirculation snorkel tube (26) and the fresh air tube (22). In this way, the blower fan assemblies (10) provide at least one scoop of fresh air (78) which is delivered to the passenger compartment (54) of the vehicle (14) through the ventilation holes (72) and the air handling system (12). According to Figures 2 to 7, the blower fan assembly (10) of the vehicle air handling system (12) may include a recirculation opening (90) and a fresh air opening (92). The recirculation opening (90) is in contact with the recirculation snorkel pipe (26), while the fresh air opening (92) is in contact with the fresh air pipe (22) which draws clean air (78) from the vents of the vehicle (14). The recirculation opening (90) and the fresh air opening (92) ensure that various quantities of clean and recirculated air (78, 82) are delivered to the blower fan assembly mixed chamber (94) where they are combined before being delivered to the passenger compartment (54) of the vehicle (14). The blower fan assembly (EQIO) may include at least one conditioned air opening (96) for supplying cooled air to the air handling system (12) (not shown in the figures). In various configurations, the blower fan assembly (10) may include a separate conditioned air opening (100) for supplying conditioned air (100) to the passenger compartment (54) at various temperatures. 1, 6 and 7, a filter (110) can be placed between the blower fan assembly (10) and the blower fan assembly (16) to remove various particulate matter from the air passing through the chamber (94) and the blower fan assembly (10) to prevent the transmission of various particulate matter to the passenger compartment (54) so that it cannot be inhaled by the occupants of the vehicle (14). The filter (110) is designed to be placed in other parts of the air handling system (12) in various configurations. An exhaust vent is placed under the blower fan assembly (10) and the fan (16) to convey air to the passenger compartment (54) of the vehicle (14). The exhaust vent (112) can be connected to one or more exhaust pipes that deliver air to various parts of the vehicle (14). A specific vehicle (14) may include more than one blower air assembly for air circulation to the passenger compartment (54) of the vehicle (14). For ventilation purposes only and not for ventilation, a blower for air circulation and delivery may be installed at the front of the vehicle (14) and a separate blower may be installed at the rear of the vehicle (14). Alternatively, blowers for air circulation and delivery may be installed on the right and left sides of the vehicle (14). In various configurations, the air handling system 12 may include multiple functions designed to deliver air to the passenger compartment 54 at various temperatures. One of these functions may include a throttling function that may be initiated when the vehicle 14 is initially running and/or when the interior air conditioning of the passenger compartment 54 is substantially above a predetermined cabin air temperature. In such a configuration, when the air conditioning is running to engage the throttling function, the return air diverter 18 is placed in the full recirculation position 24, thereby drawing the maximum amount of recirculated air 82 from the passenger compartment 54 into the recirculation snorkel pipe 26 and blower fan assembly 10. Similarly, a minimum amount of fresh air (78) is drawn through the fresh air pipe (22) through the blower fan assembly (10). In such a structure, the recirculated air (82) drawn into the recirculation snorkel pipe (26) and the blower fan assembly (10) is continuously cooled after being blown through the air handling system (12) to further reduce the air flow in order to maximize the cooling effect of the air conditioner. Indirectly, the reduction function can be adjusted to a considerably lower speed than if the recirculated air (82) were not delivered to the passenger compartment (54). Other functions of the air treatment system (12) may include a protection function, according to which the air from the air conditioner may be mixed with air from the recirculation snorkel pipe (26) in order to protect the air circulating through the blower fan assemblies (10) from specific air leakage. By mixing the recirculated air (82) with the air from the air conditioner, the air conditioner may operate more efficiently and use less resources than the air treatment system (12). According to figures 3 to 5, the return air/preventer (18) may have multiple recirculation positions (`i24). The recirculation positions (24) may be adjusted according to each of the vehicle. (14) The difference in the incoming air can be mixed with the recirculated air (82) from the passenger compartment (54) at a predetermined rate in some cases, re-conditioned if desired, and re-circulated to the passenger compartment (54) of the vehicle (14). Various settings or functions of the air handling system (12) can change the position of the return air diverter (18) to allow more or less amounts of recirculated air (82) to pass through the blower fan assemblies in contrast to the fresh air (78). For the purpose of clarification rather than conditioning, the air handling system 12 may include a cooling setting whereby the air in the passenger compartment 54 of the vehicle 14 passes substantially beyond a certain desired cooling point by the occupants of the vehicle 14. In such a case, the return air diverter 18 may be placed in the full recirculation position, so that the majority of the air carried by the blower fan assemblies 10 is recirculated air 82 drawn from the passenger compartment 54 through the recirculation snorkel pipe 26. At the same time, the full recirculation position typically results in a smaller proportion of fresh air being drawn from the recirculation air 82 than from the vehicle through the fresh air pipe 22. (14) can be provided to the passenger compartment (54). As the humidity of the passenger compartment (54) approaches the desired set point, the return air diverter (18) can be configured to change positions to condition smaller amounts of recirculated air (82) and larger amounts of fresh air (78) and to provide the blower assembly (10) from the opposite room to the passenger compartment of the vehicle (14). In various configurations, as shown in Figures 1 through 7, the air handling system 12 may include an air conditioning unit (not shown in the figures) connected to the blower fan assembly 10 and the vehicle 14 may include an air conditioning unit (not shown in the figures) connected to the blower fan assembly 10 for the air handling system 12. Accordingly, the air conditioning unit and the blower fan assembly 10 may be used to condition the air in the vehicle. In various configurations, the air conditioning unit may function together with the provision of conditioned air (100) to be placed in the blower fan assembly (10) having a predetermined flow rate, which is separated from the air handling system (12) for delivery to the passenger compartment (54). Fresh air (78) may be drawn into the blower assembly (10) through various recirculation positions of the return air/air conditioner (18). These functions may function together to regulate both the convenience of the conditioned air (100) delivered to the passenger compartment (54) and the connection to the air conditioner (100). Again, according to Figures 1 and 7, when one of the recirculation functions of the air treatment system 12 is operating, the recirculation air 82 is drawn into the noise reduction duct 28 of the recirculation snorkel tube 26 located under the instrument panel 30 of the device 14. In this way, noise originating from the fan 16, the air conditioning or other feature of the air treatment system 12 can circulate through the blower fan assemblies and also through the recirculation snorkel tube 26. The noise, sometimes referred to as broadband frequency noise (118) resulting from these different components of the air handling system (12), can pass through the noise reducer (28) of the recirculation snorkel pipe (26) into the passenger cabin (54) of the vehicle (14). In order to minimise the amount of broadband frequency noise (118) directed to the upper sections of the passenger cabin (54) where it can be heard by the occupants of the vehicle (14), the noise reducer (28) of the recirculation snorkel pipe (26) is directed to the floor (32) of the passenger cabin (54) of the vehicle (14). In various configurations, the floor 32 below the instrument panel 30 of the vehicle 14 is substantially horizontal to the passenger compartment 54. In such conditions, the recirculation snorkel pipe 26 is positioned substantially vertical to the floor 32, and in this way the broadband frequency noise 118 originating from the noise attenuator 28 of the recirculation snorkel pipe 26 is directed to the floor 32 of the passenger compartment 54. In various configurations, as shown in Figures 1 through 7, the placement of the recirculation snorkel tube (26) in relation to the blower fan assembly (10) reduces the amount of air turbulence entering the recirculation snorkel tube (26) and the blower fan assembly (10) by means of a noise reduction device (28). The reduction in the amount of air turbulence serves to reduce overall system noise and improve the performance of the air handling system (12). The advantage of this arrangement of the recirculation snorkel pipe 26 is that the recirculation snorkel pipe 26 provides a noise escape route through the noise attenuator 28 which is directed towards the floor below the instrument panel 30. In this way, noise is directed away from the heads and ears of the occupant of the vehicle. Referring to Figure 1, various alternative configurations may include the floor 32 of the passenger compartment 54 being opened upwards from a horizontal position and the vehicle 14 being opened upwards where the instrument panel 30 passes substantially below. In such a case, the noise reducing end 28 of the recirculation snorkel pipe 26 may be placed vertically at the footrest of the floor 32 of the instrument panel 30 below the vehicle 14. In this manner and as indicated above, the broadband frequency noise 118 leaving the noise reducing end 28 of the recirculation snorkel pipe 26 is directed vertically to the floor 32 of the vehicle 14. In various configurations, the floor 32 of the vehicle 14 below the instrument panel 30 may comprise a covered surface or another surface covered with textile material. By directing the broadband frequency noise 118 through the noise reducer 28 of the recirculation snorkel tube 26 and the carpet/or textile ends of the floor 32, the broadband frequency noise 118 can be absorbed to a minimum extent on the floor 32 without causing significant reverberation of the broadband frequency noise 118 in the upper areas 130 of the passenger compartment 54 where such noise would be significantly audible to occupants of the vehicle 14. Again, in accordance with Figures 1 to 7, the noise reducer end 28 of the recirculation snorkel tube 26 is positioned below the instrument panel 30 of the vehicle 14. The various cooling functions of the air handling system (12) of the vehicle (14) are operated as follows: The conditioned air (100) is delivered to the passenger compartment (54) through blower fan assemblies (10). The conditioned air (100) in the passenger compartment (54), which is generally colder and more humid than the IDE air, travels through the lower vents of the vehicle (14). Accordingly, the cold air delivered to the passenger compartment (54) through one of the cooling functions of the air handling system (12) may tend to collect in the lower front area (52) of the passenger compartment (54) near the floor (32) below the instrument panel (30) of the vehicle (14). The placement of the recirculation snorkel tube (26) over said areas results in the collection of cooler conditioned air (100) in the recirculation functions of the air handling system (12) by the means (14). By collecting said cooler air in the lower front area (52) of the passenger cabin (54), the air conditioning and air handling system (12) as a whole is placed under less stress in order to reduce the heat of the air being forced through the recirculation snorkel tube (26) by the blower fan assembly (10) as opposed to the air being forced into the upper areas (130) of the passenger cabin (54). Since the air in the lower front area 52 of the passenger compartment 54 is colder, the desired air conditioning set points in the passenger compartment 54 can be reached in a relatively short time due to the lower temperature of the recirculated air 82 introduced to the air handling system 12. In this way, the time required to operate the air conditioner without a throttling function or other cooling function is reduced. Consequently, the air handling system 12 and the vehicle 14 as a whole can operate more efficiently by utilizing the cooling resources of the vehicle 14 and its various systems. In various configurations, the return air baffle of the air handling system 12 may include first and second baffles located near the fresh air pipe 22 and the recirculation snorkel pipe 26. In such a configuration, the first baffle operates independently to control the amount of fresh air 78 that is forced into the system. Similarly, the second baffle is located near the recirculation snorkel pipe 26 and controls the amount of recirculated air 82 that is drawn in by the blower fan assembly. In the operating state, the first and second diverters can be operated in a connected manner in order to specifically regulate the amount of fresh air 78 brought into the air handling system 12 for re-conditioning and delivery to the passenger compartment 54 of the vehicle 14. In cases where two diverters are provided, the first diverter, which controls the amount of fresh air 78 drawn into the cabin, remains open at least partially. In this case, the recirculated air 82 delivered to the passenger compartment 54 during operation of the air handling system 12 contains at least a small amount of fresh air 78. 8 through 11, the blower fan assembly 10, including the recirculation snorkel tube 26, can be manufactured in various configurations, with the blower fan assembly 10 being manufactured with a recirculation snorkel tube 26 pre-mounted onto the blower fan assembly 10. In this manner, the blower fan assembly 10 may include a snorkel tube adapter 140, which may enable the blower fan assembly 10 to be mounted on various vehicles as part of the vehicle air handling system. The snorkel tube adapter 140 may then be connected to a snorkel tube extension 142 which extends from the snorkel tube adapter 140 to the final location of the noise reducing valve 28 of the recirculation snorkel tube 26. In this manner, the combination of the snorkel tube adapter 140 and the snorkel tube extension 142 forms the recirculation snorkel tube 26 for the blower fan assembly 10. In such a configuration, a single blower fan assembly with a snorkel tube adapter 140 can be fabricated, thereby minimizing the cost of fabricating several different recirculation fan assemblies, each of which includes a separate recirculation snorkel tube 26, that are connected to the assembly. In this configuration, multiple different designs for the snorkel tube attachment 142 can be implemented and manufactured. Each design can be adapted to suit different make, model and/or trim of vehicle, which may include a recirculation snorkel tube 26 for a particular vehicle 14 air handling system 12. Again, as indicated in Figures 8 through 11, the snorkel tube adapter 140 can be constructed to cover the recirculation opening 90 of the blower fan assembly 10 which is in contact with the return air guide 18. When installed in a given vehicle 14, the snorkel tube attachment 142 is connected to the snorkel tube adapter 140 to form the recirculation snorkel tube 26 as a whole in a given vehicle 14. In various constructions, the recirculation snorkel tube 26 is not resistant to moisture caused by air passing through it. Such materials may be, but are not made of, plastic, metal, composite, combinations thereof, or other rigid materials. In addition, the recirculation snorkel tube 26 may include an insulation layer placed over a portion of the recirculation snorkel tube 26. The insulation layers 14 serve to protect air passing through the recirculation snorkel tube 26 as it is conveyed to the passenger compartment 54. Various modifications are possible to the above described structures without departing from the concepts and scope of the present invention, and furthermore, such concepts are within the scope of the following claims unless otherwise stated.

Claims (1)

1. CLAIMS A vehicle air handling system including: a blower fan assembly for a vehicle and a return air deflector operating between the fresh air position where the fan is in contact with the fresh air pipe and the recirculation position where the fan is in contact with the recirculation pipe at least as much as possible; and a noise reducer located below the vehicle instrument panel and wherein the noise from the fan drawing air through the recirculation pipe is directed to the floor below the instrument panel, the recirculation pipe being directed substantially vertically with a height of one inch below the instrument panel. The vehicle air handling system according to claim 1, wherein the noise reducer of the recirculation pipe is arranged to draw air from the lower front area of the vehicle passenger compartment near the floor below the instrument panel. The vehicle air handling system according to claim Z, wherein the longitudinal axis for noise reduction is located substantially normal to the floor below the instrument panel. The vehicle air handling system according to claim Z, wherein the recirculation position of the return air diverter/vent is determined by the fan being in contact with the fresh air pipe and the recirculation pipe. The vehicle air handling system according to claim 2, wherein the return air diverter has multiple recirculation positions, each of said multiple recirculation positions containing a predetermined proportion of fresh air from the fresh air pipe and recirculated air from the recirculation pipe. The vehicle air handling system according to claim 1, including: The return air diverter is positioned in the recirculation position of the air conditioning system. The return air diverter includes a first diverter located near the fresh air duct and a second diverter located near the recirculation duct, the first and second diverters functioning together to regulate the amount of fresh air and recirculated air drawn in by the blower fan assembly. The vehicle air handling system according to claim Z, including: The fan includes a blower fan assembly, having an upper end in contact with the fan and a noise reducing device located near the lower front air duct of the passenger compartment and directed substantially vertically to the floor in the lower front air duct, and wherein the noise from the fan is directed to the floor in the lower front air duct of the passenger compartment, in order to reduce the noise from the fan to the lowest point of the interior. The vehicle air handling system according to claim 8, wherein the noise-reducing end of the recirculation pipe is arranged to draw air from the lower front seat of the vehicle passenger compartment near the floor below the vehicle dashboard. The vehicle air handling system according to claim 9, further comprising: A return air diverter positioned with a blower fan assembly operating between the fresh air position where the fan of the return air diverter is in contact with the fresh air pipe and the recirculation position where the fan is at least partially in contact with the recirculation pipe. The vehicle air treatment system according to claim 9, wherein the recirculation position of the return air diverter is determined by the fresh air pipe and the fan in contact with the recirculation pipe, wherein the noise reducer includes a longitudinal axis, said longitudinal axis being located substantially normal to the floor below the instrument panel. The vehicle air treatment system according to claim 10, wherein the return air diverter includes a plurality of recirculation positions, said plurality of recirculation positions each providing a predetermined ratio of fresh air from the fresh air pipe and recirculated air from the recirculation pipe. The vehicle air handling system according to claim 10, wherein the return air handler includes a first handler disposed near the fresh air pipe and a second handler disposed near the recirculation pipe, the first and second handlers functioning to regulate the amount of fresh air and recirculated air drawn in by the blower fan assembly. The vehicle air handling system including: A blower fan assembly disposed in the vehicle dashboard and having a longitudinal axis in contact with the fan, the longitudinal axis of which is disposed substantially normal to the surface located below the vehicle dashboard, and the noise from the air handler is directed to the surface of the floor in order to reduce noise. The vehicle air handling system according to claim 15, wherein the recirculation pipe is arranged to draw air from the lower front area of the vehicle passenger compartment near the floor below the vehicle instrument panel. The recirculation pipe includes an upper end located near a return air diverter which is connected to the blower fan assembly and the blower fan assembly; the return air diverter operating between the fresh air position where the fan is in contact with the fresh air pipe and the recirculation position where the fan is at least partially in contact with the recirculation pipe. The vehicle air handling system according to claim 16, wherein the recirculation position of the return air diverter is determined by the fresh air pipe and the fan in contact with the recirculation pipe. The vehicle air treatment system according to claim 17, wherein the return air diverter/vent has a plurality of recirculation positions, and each of said plurality of recirculation positions includes a predetermined ratio of fresh air from the fresh air pipe and recirculated air from the recirculation pipe. The return air diverter includes a first diverter located near the fresh air pipe and a second diverter located near the recirculation pipe, the first and second diverters functioning together to determine the amount of fresh air and recirculated air drawn in by the blower fan assembly, the vehicle air treatment system according to claim 17.